Automatic gun having sliding barrel



March 14, 1944. w. ROSSMANITH 2,344,109

. AUTOMATIdGUN HAVING SLID'ING BARRELS Filed July 18, 1939 S A 1 A 9 3 O 8 4a 6a 4b Patented Mar. 14, 1944 AUTOMATIC GUN HAVING SLIDING BARREL Wolfgang Rossmanith, Solothurn, Switzerland; 7 vested in the Alien Property Custodian Application July 18, 1939, Serial No. 285,144

In Germany July 16, 1937 1 4 Claims.

' the barrel in its rear position until the lever is swung out of the notches by the breech block during its return movement. If these locking levers are not positively actuated the reliability of their action is doubtful, while known positively actuated arresting devices cause friction and stoppages by bearing against the rearwardly running breech block.

Thus, an automatic gun having an arresting device controlled positively by a driving lever which consists of an arresting lever connected rigidly with the driving lever has been proposed, in which case the lever and the breech block act directly on each other and maintain constantly their engagement with each other during the entire period of action of the gun, that is to say during both the recoil and the return movements. If the barrel is subjected to a forward driving action, for instance by the barrel return spring or the effect of the weight of the moving parts when firing downwards, then the driving lever will be pressed against the backwardly running breech block with a resulting checking and frictional effect.

' The invention, by means of an arresting device controlled positively by the driving lever, which, without friction or checking the movement of the breech block, ensures that the barrel shall be held reliably in the position necessary for locking with the breech block by an automatic checking action between the driving lever and the arresting device. According to the invention, with this object in view, th driving lever is arranged to actuate a separately mounted arresting lever into its arresting position by means of a control cam surface. By means of a suitable form of construction of the control cam surface it is ensured that the period of engagement of the arresting lever in the barrel persists during a part of the recoil path shortly before the beginning of the unlocking operation and until the end of the recoil movement of the barrel. Furthermore, checking action of the control cam surface of the driving lever on the arresting lever, ensures that in all circumstances a premature return of the barrel into its front end position is prevented and the arresting lever in its turn prevents accidental return of th driving lever,

while during the return movement of the breech block the arrestin lever cannot move away before the locking position is reached. In order, when the breech block is initially withdrawn by hand for the cocking and loading of the gun, that the barrel and the driving lever shall make the same movement as when a shot is fired and the barrel shall join in the return movement into its rear end position, it is advisable to provide a separate projection on the driving lever which is carried along by the withdrawn breech block.

In the accompanying drawing, which shows diagrammatically as an example of construction, an arresting device for automatic guns according to the invention:

Figure 1 is an elevation in part section of the barrel, breech bolt and associated parts of a firearm equipped with the device,

Fig. 2 is a similar view showing the parts when the unlocking of the barrel commences,

Fig. 3 is a similar view showing the parts during the acceleration of the breech block, and- Fig. l is a similar view showing the parts at the end ofthe acceleration of the breech block.

Referring to the drawing, the breech block is connected, in known manner, with the barrel I which is slidingly mounted in a gun casing 2, for example by the usual locking sleeve which is adapted to turn during the common rearward movement of both parts. The barrel l and the breech block 2 may be arranged to run back against the action of special return devices or, as shown in the drawing, against the action of a common closing spring 3.

Pivotally mounted in the gun casing on a pin 5 is a driving or actuating lever 4. This driving lever co-operates with a barrel arresting lever B which is adapted to pivot about a pin 1 in the gun casing and has projection 6a which slides on a cam surface 4b of the driving lever l; Stops Band 9 limit the rotation of the lever d in both the clockwise and anti-clockwise directions.

The barrel or the end of the barrel casing I has a projection la the rear surface ofwhich strikes, during the rearward movement of the locked-barrel and breech block, against a surface ta on the lever 4 and thereby causes the leverarm nose 412 to swing into position in front. of

rearwards bythe driving lever, while at the same" time the barrel projection la slides on the surface to which is so shaped that the effective leverage of the barrel about the pivotal support of the driving lever is continuously reduced, whereas the lever-arm nose 4d acts upOn the shoulder 2a, with constantly increasin leverage, so as to ensure an increasingly accelerated rearward movement of the breech-block 2 relatively to the barrel I.

When the driving lever 4 is engaged between the end surface of the barrel and the shoulder 2a on the breech block (as shown in Fig. 2), the nose 6a of the arresting lever 6 slides on the cam surface 412 of the driving lever 4 and is positively adjusted thereby in such a, manner that the nose 6b engages behind th projection Ia on the barrel. During the continued movement of the driving lever 4, the diameter of the part of the cam surface 4b which is engaged by the nose Ea increases after the manner of a spiral to continue the cam face along a line sub-' stantially concentric to the pin 5, and so the nose Eb is more and more lifted onto the barrelarresting surface (Fig. 3) until finally the lever 4 turns into its end position (as shown in Fig. 4) and the barrel I has arrived in its rear end position, also shown in Fig. 4. The barrel I will now be held securely in its rear end position by the lever 4 while the breech block, owing to the kinetic energy transmitted thereto by the barrel I by way of the lever 4, runs back alone. A reversed motion, i. e. anti-clockwise motion, of the lever 4 and, therefore, a forward movement of the barrel I is prevented by the automatic checking efiect due to the fact that the pitch of the cam surface 41) at the point of contact with nose So, when the parts are in the position shown in Fig. 4, is so slight as in effect to lock the lever 6 against rotation in counterclockwise direction. When the breech block 2 runs back into the barrel I which is arrested in its rear end position it swings the lever 4 which allows the arresting lever B to swing gradually out of its barrel-locking position. The duration of the period of engagement of the lever 6 until the final release of the. barrel occurs is, in this case, so selected that a sliding of the arresting lever nose 6b from the barrel projection Ia is not completely ended until the locking of the barrel and block has already begun. The barrel I and the breech block 2, the locking having in-the meantime taken place,.then move together into the firing position shown in Fig. 1.

In order, during the initial cooking of the gun by the withdrawal of the breech block 2, that the barrel I be returned into its rear end position the lever 4 is provided with the projection 40 against which the projection M on the breech block 2 bears when it is withdrawn, so that the lever 4 and the arresting lever 6 are adjusted in the same way as is the case during automatic firing.

I claim:

1. An automatic gun comprising a sliding barrel, a sliding breech bolt capable of being locked and unlocked with respect to said barrel and longitudinally movable with respect thereto, a casing in which said barrel and breech bolt are movable, a lever arranged to arrest the barrel at the end of its rearward movement, said lever being pivoted in said casing, and an actuating lever pivoted in said casing independently of the arresting lever and having a cam surface thereon co-operating continuously with the arresting lever to move it into and out of operative operative portion for moving the arresting lever into barrel holding position towards the end of the barrel recoil movement, and a holding portion for retaining the arresting lever in such position during the subsequent movements of the breech bolt until the latter returns to locking position on the barrel.

2. An automatic gun according to claim 1, in which the cam surface on the actuating lever has a substantially concentric holding portion H V forming a positive obstruction to reverse movement of said actuating lever while said cam portion engages the arresting lever.

3. An automatic gun comprising a sliding barl'el, a sliding breech bolt capable of being locked and unlocked with respect to said barrel and longitudinally movable with respect thereto, a casing in which said barrel and breech bolt are movable, a lever arranged to arrest the barrel at the end of its rearward movement, said lever being pivoted in said casing, and an actuating lever pivoted independently of the arresting lever and having a cam surface thereon cooperating continuously with the arresting lever to move it into and out of operative position, said actuating lever having means engaged by the recoiling barrel for swinging said actuating lever in one direction and means engaged by the sliding breechbolt for swinging said actuating lever, in the opposite direction, the cam surface on the actuating lever having an operative portion for moving the arresting lever into barrel holding position towards the end of the barrel recoil movement and a holding portion for retaining the arresting lever in such position during the subsequent movements of the barrel, and a heel on said actuating lever lying in the path of the breech bolt movement away from the barrel.

4. An automatic gun comprising a sliding barrel, a sliding breech bolt capable-of being locked and unlocked with respect to said barrel and longitudinally movable with respect thereto, a casing in which said barrel and breech bolt are movable, a lever arranged to arrest the barrel at the end of its rearward movement, said lever being pivoted in said casing, and an actuating lever pivoted in said casing independently of the arresting lever and having a cam surface thereon contacting continuously with the arresting lever to move it into and out of operative position, said actuatinglever' having means engaged by the recoiling barrel for swinging said actuating lever in one direction and means engaged by the sliding breechbolt for swinging said actuating lever, in the opposite direction, the cam surface on the actuating lever having an operative portion for'moving the arresting lever into barrel holding position towards theend'of the barrel recoil movement, and a holding portion for retaining the arresting lever in such position during the subsequent movements of the breech bolt until the latter returns to locking position on the barrel.

WOLFGANG ROSSMANITH. 

